Polyimides are polymers synthesized from bifunctional carboxylic anhydrides and primary diamines; among polyimides, aromatic ones exhibit superior mechanical characteristics, heat resistance and oxidation resistance, so they are extensively used in such fields as electronic devices and aircrafts.
In addition, polyimides also excel in lubricating property and biocompatibility, so using them as solid lubricating films and the like that are formed on substrates is under review in such fields as medical appliances.
A specific example that has been proposed is a medical wire insert characterized by having a coated wire comprising a core wire and a polyimide coat formed on its surface by vapor deposition polymerization (see Patent Document 1). According to Patent Document 1, the medical wire insert has high lubricating property, can smoothly travel through a medical annular device, has a suitable degree of stiffness, is easy to handle, and even has great peel strength.
Patent Document 1: JP 2001-238963 A